1. Field of the Invention
The present invention relates in general to vending machines having helical dispensing coils and, more particularly, to an improved configuration for the forward end of a product shelf in such a machine comprising a support member for rotatably supporting the front end of an elongated helical coil above the surface of the shelf.
2. Description of the Prior Art
The use of helical coils in vending machines as a means for transporting articles to be vended from a location in the interior of the machine to a discharge point is well known. Typically, the vending coil is used in conjunction with a horizontal support tray or shelf. The articles to be vended are placed within the convolutions of the vending coil and are supported by the tray or shelf. Upon rotation of the vending coil, the articles to be dispensed is longitudinally advanced along the shelf until it reaches the front end of the shelf. Upon further rotation of the vending coil, the article to be dispensed is forced over the front edge of the shelf and falls into a discharge bin where it may be manually removed by the person operating the vending machine.
U.S. Pat. No. 3,993,215 to Cox et al illustrates a vending coil support structure typically used in the prior art. In the Cox structure, the dispensing coil rides within a trough formed within a shelf. The forward end of the shelf is configured to form a notch, when viewed above, with a forwardly projecting ledge at one side of the notch. The dispensing coil is disposed with its forward end extending over the notch and the lower end of its forwardmost convolution extending over the notch to support the next item to be dispensed at one side thereof above the notch, with the other side of the item being supported on the projecting ledge. During a dispensing cycle, as the coil rotates, the lower convolution portion which supports the item to be dispensed is withdrawn from beneath the item, allowing the item to tip sideways and to fall under the force of gravity through the notch and into an underlying collection bin.
The Cox apparatus was specifically designed for vending machines having relatively closer tolerances between the front of the helix and the front door of the cabinet, where it is desirable to cause the item being dispensed to tip to the "side" rather than "forward" during the dispensing cycle. This apparatus was particularly designed for dispensing relatively light-weight bag packaged articles such as potato chips, pretezels and the like which would have a tendency to hang-up or become bridged between the shelf and the front door of the machine, if such articles would be dispensed so as to tip-over in the forward longitudinal direction of the coil. While the side-tipping dispensing apparatus of Cox addressed the bridging problem associated with dispensing bag-type articles, the structure was susceptible to jamming or catching of the bag-type package being dispensed between the lower surface of the dispensing coil and the upper surface of the trough.
The inventor's prior U.S. patent application Ser. No. 669,348 filed Mar. 22, 1976, now issued as U.S. Pat. No. 4,061,245, described an improved helical-coil dispensing apparatus, generally operable in a side-tipping manner, which overcomes the jamming or catching deficiencies of the Cox-type apparatus. This apparatus does not require a coil-guide trough along the entire length of the dispensing coil, but has means for supporting the opposite ends of the dispensing coil such that the lower most portions of the opposite ends are exposed above and spaced from the horizontal shelf surface on which the items to be dispensed are being supported. A coil support member mounted at the forward end of the shelf is configured to rotatably support the forward end of the coil such that the lower extremity of the coil does not engage the shelf surface, and thus cannot catch the package of the article being dispensed therebetween.
One type of such support member for the forward end of the dispensing shelf is disclosed in FIGS. 4-6 of the Inventor's above-referenced prior patent. Such a support member includes two parallel, transversely spaced coil support members having upper planar surfaces disposed above the level of the shelf surface, for supporting the dispensing coil thereon. A first end of each of the coil support members is provided with an upwardly extending ramp which guides articles to be dispensed and moved by the coil from the primary shelf surface to the upper planar surfaces of the coil support members. A second end of one of the support members projects outwardly beyond the front end of the shelf, and the second end of the other coil support member terminates at a position approximately coincident with the front edge of the shelf. This forms, in effect, a laterally offset notch as viewed from above, at the forward end of the shelf. The article to be next dispensed is supported and dispensed in a manner similar to that above-described with respect to the Cox apparatus.
While both of the above-described side-tipping dispensing structures work effectively with relatively light-weight bagpackaged type items such as potato chips and pretzels, their structure is less effective for dispensing relatively heavy or bulky boxed items, for example, those candy box sizes commonly known in the art as "theatre packs". When such heavy or bulky boxed items are supported in a cantilever manner by the forwardmost convolution of the helical coil as above-described, the weight of the article to be dispensed can distort the forwardmost convolution extending over the notch, and can occasionally allow the box to slip through the coil and drop into the collection or discharge bin before the vending cycle has been initiated. When further considering the thickness of the box to be dispensed, the distance between adjacent convolutions must be increased, further adding to the above-described potential problem.
The present invention overcomes the deficiencies of the prior art helical coil dispensing structures for dispensing heavy or boxed items by providing a level coil support apparatus for mounting at the forward edge of a shelf, which gives positive and reliable forward-tipping dispensing of such items in an efficient and tamper-proof method.